Re: Analysis of an 11 year old, 165K mile battery pack
 

I went on the freeway and it seemed to still have e-assist at 75mph it might be higher but there was a lot of CHP so I did not want to push my luck

class 0 gloves are required when taking it off

but once the bus bars are off the volts drop to 7-8 volts
but i have been shocked by 600volts DC (CCFL inverter )touched a live part I did not get burned or anything

but you can feel the power in your hand... not enough current in those things to do anything.
I really wish they had manual control over the EV and auto stop...and engine mode

this way the driver could optimize their fuel savings.. what if i'm on a down hill ? I could run on EV mode pretty much the whole way and run normal mode on the way back.. etc..

un like the traditional auto stop we got Electric power steering and AC etc


basically it's configured for areas with 25mph speed limit in mind.. and if you don't live in this areas you can't get the full benefits.

Re: Analysis of an 11 year old, 165K mile battery pack
 

You're working on a lot of invalid assumptions - 1) GM spent a lot of time optimizing this system. You're highly unlikely to do better. 2) the usable capacity of the HV battery is about the same as the total capacity of the 12V battery under the hood (how far do you expect to drive on the 12V alone?) and 3) This car is 100% gas. Period. Every joule of propulsive energy comes from gas. Any "EV mode" battery consumption has to be replaced with either recovered kinetic energy or most often gas.

12V/70Ah = 840Wh of electrical energy
288V/6.5Ah (40% utilized) = 749Wh of electrical energy.

The HV battery is not for propulsion in the EV sense. It's for kinetic energy recovery, release, for supplemental power where the ICE is least efficient and for power during auto-stop.

Just because the ICE is running, it doesn't mean it's providing any significant power or burning much gas. On a downhill, the ICE is still running, but depending on the gradient, you may even be charging the HV battery.

If you were to record your drives, you would find that every single drive results in more capacity being put into the HV battery than being extracted - due to inefficiencies. Where did that come from? Gas.

Concerning the bolded bit above, that is patently untrue. I'm guessing you're new to hybrids. This type of "MOAR EV mode!" thinking is common for those that don't understand how they work.

Re: Analysis of an 11 year old, 165K mile battery pack
 

ev mode is good for 2 miles. if iwas able to get it to 40-45 then ICE kicks in it would benifit so much more ..


my city speed limits arr 40 to 60mph with traffic lights. initial start is when you waste the most amount of gas. if iwas able to to get to 40mpg before ice kicks in id be crusing at or near optimal speed for maximum
​​​ MPG

Re: Analysis of an 11 year old, 165K mile battery pack
 

These GM Two Mode SUV vehicles are heavy 5,270 to 5,527 lbs curb weight. It requires a lot more energy to make it move than a Prius (aka penalty box) which weighs 2,932 lbs about 1/2 as much. Best I can tell the GM Two Mode control systems utilizes a good portion of the battery systems potential as programmed from GM. it seems that after a few years the battery pack is pretty much USED UP. If you started utilizing even more of the battery potential below the threshold SOC and charging above it you would probably only have your stellar performance for a short period of time and then have a trashed battery pack............ Now that I have gotten interested in Electric vehicles I am thinking about ordering myself a Tesla Y SUV they look pretty cool.

Re: Analysis of an 11 year old, 165K mile battery pack
 

no the problem with AC motors is the in rush current I don't think they dealt with it with large enough capacitors 60KW and the inrush peak current will be 65-70kw or so. yeah it is PWM controlled

I know gm claims it's a delicate system as they claim it is
But if that is the case why is the DC to DC converter is 185amps (13/15v DC) to run accessories
185amps is pretty beefy system considering 145/160 amp is a "stock unit"...

The A/C runs straight off the 300VAC 3 phase (it's more reliable this way anyways then running a lower voltage air conditioning)..


a large 350V capacitor (does not have to be a single cap)(has to be rated higher then the input since that will be about 320-325v) buffer system would help in the longevity of the battery. placed in parallel with the battery ..

Re: Analysis of an 11 year old, 165K mile battery pack
 

old thread but this is interesting. cooling seems to be everything. I haven't had mine apart, but do we know if this is a brushed or brushless cooling fan? being gm I wonder if you can cross reference it to a newer brushless fan, or at least one that's designed for more rpm per the given voltage. we used to call this kv in the rc world. so it would then put out the same info to the bcm just spin faster giving the same pwm signal and using more power. also they make boxes now for cars with dead headed fuel systems, controlled by pwm, they can step up the voltage at wot for more fuel flow needed and then return to normal. it's adjustable, so you might be able to adjust it just before it sets a code. most 12v fans will handle 16v without hurting anything.

on another cooling thought. again I've not had the battery apart but is there enough room to put very thin aluminum or copper plates between each pack, and have it stick out some as a heat sink, using the same amount of air already there, just cool the center packs better? I did this once to an rc plane motor, it was very overly proped for its size to make the plane fly well, it would come down over temp, but a quick flat piece of aluminum between the motor and the mount, and some cuts to make fins. there was no noticeable drag flying but came down well within normal Temps.

just a thought I had while reading thru.

Re: Analysis of an 11 year old, 165K mile battery pack
 

https://cimg5.ibsrv.net/gimg/www.gre...eb835235c8.jpg
Zero room between modules for a cooling plate